Typical light sources (e.g., incandescent, fluorescent lights) produce nearly white light. However, color filter devices for controlling the color of lights used for photography, public performances (e.g., stage performances, concerts, sporting events), film-making, architectural design (e.g., wall wash fixtures, spotlights, accent lighting, outdoor lighting), and other similar applications are well known. The most common type of color filter device are dyed gels of various colors that are placed over a white light source (hereafter, “light source”) to create a colored light. In some devices, each gel must be manually placed over the light source and must be manually replaced with another gel if a different light color is required. Other devices comprise different colored gels attached to a rotatable roller located in the path of the light source (e.g., the Coloram II, a color scroller made by Wybron). The roller is rotated to place a desired colored gel in the light path to provide the desired colored light. Unfortunately, the mechanical system used to operate the rollers is expensive and subject to breakdowns. In addition, the movement of the gels can cause the gels to rip or tear. Further, the rotating roller devices are only capable of producing a limited number of different colors because only a limited number of gels are available for positioning in the light path. Furthermore, it takes a significant amount of time to switch between colors. Moreover, a major disadvantage in using gels is that the colors produced by the gels are unsaturated. Further, the gels tend to bleach out after long exposure to the high power light sources used in the foregoing devices.
Prior art devices attempt to solve the foregoing problems but each has a problem in utilization that makes it relatively unattractive to manufacture or use. For example, instead of gels, some devices (e.g., the Vari-lite VL2C™) use vacuum deposited thin film layers of dichroic materials that selectively reflect part of the visible spectrum while passing other parts of the spectrum. The dichroic filters are attached to a wheel that can be rotated to place different color filters in the path of a light source. However, mechanical switching makes these devices slow in switching between colors and prone to mechanical breakdown. In addition, such devices are relatively expensive because of the vacuum deposition process used for producing the dichroic filters. Moreover, such devices are limited to stage lighting or film-making applications. Other devices require complicated and/or expensive mechanisms. See, for example, U.S. Pat. No. 6,252,638 to Johnson et al. and U.S. Pat. No. 5,689,317 to Miller. Accordingly, it is a broad object of the invention to provide a color filter that is relatively inexpensive, easy to manufacture, reliable, and simple to maintain and operate.